The first time you click on a bool cell, there may not be an active cell renderer at this point. This means your code in teh checkboxclick event is being skipped as you are checking the renderere at the beginning. Try this code.
private void gridGroupingControl1_TableControlCheckBoxClick(object sender, Syncfusion.Windows.Forms.Grid.Grouping.GridTableControlCellClickEventArgs e)
{
GridTableCellStyleInfoIdentity tableCellInfo = e.TableControl.Model[e.Inner.RowIndex, e.Inner.ColIndex].CellIdentity as GridTableCellStyleInfoIdentity;
GridRecord rec = (tableCellInfo.DisplayElement as GridRecordRow).ParentRecord;
object o = rec.GetValue("boolCol");
bool bTest = (o == DBNull.Value) ? false : (bool)o;
Console.WriteLine(" Fired : " + bTest + " " + rec.GetValue("Col3").ToString());
if (bTest)
{
rec.SetValue("Col3", 1);
}
else
{
rec.SetValue("Col3", 0);
}
rec.EndEdit();
}